U.S. patent number 6,125,645 [Application Number 09/017,341] was granted by the patent office on 2000-10-03 for moisture removal phase shift personal cooling garment.
Invention is credited to Stephen T. Horn.
United States Patent |
6,125,645 |
Horn |
October 3, 2000 |
Moisture removal phase shift personal cooling Garment
Abstract
The present invention provides a body cooling garment to easily
and effectively protect the human body in hot conditions. By
suspending in vapor contact a cold surface with channels in it's
surface; moisture is evaporated from the body, condensed on the
cold surface, and the body shielded from environmental heat. The
condensed moisture is channeled from the garment.
Inventors: |
Horn; Stephen T. (White Stone,
VA) |
Family
ID: |
26689745 |
Appl.
No.: |
09/017,341 |
Filed: |
February 2, 1998 |
Current U.S.
Class: |
62/259.3; 2/458;
2/DIG.1 |
Current CPC
Class: |
A41D
13/0056 (20130101); A62B 17/005 (20130101); A61F
7/106 (20130101); A61F 2007/0233 (20130101); Y10S
2/01 (20130101) |
Current International
Class: |
A41D
13/005 (20060101); A41D 27/28 (20060101); A41D
27/00 (20060101); A62B 17/00 (20060101); A61F
7/10 (20060101); A61F 7/00 (20060101); F25D
023/12 () |
Field of
Search: |
;62/4,259.3,530,457.2
;2/904,DIG.1,DIG.5,458 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Doerrler; William
Parent Case Text
CROSS REFERENCE
A provisional patent application was filed on Jun. 12, 1997 the
application Ser. No. was 60/049,749 the title was Personal
Dehumidification Equipment.
Claims
I claim:
1. A method of cooling the body of a wearer of a cooling garment,
said method comprised of the following steps:
1. supporting a hydrophobic spacer means next to said body,
a) supporting a cold surface next to said hydrophobic spacer
means,
b) evaporating perspiration from said body into vapor phase
water,
c) transferring said vapor phase water through said hydrophobic
spacer means,
d) condensing said vapor phase water into liquid phase water on
said cold surface, thus cooling said body.
2. The cooling garment of claim 1 wherein said cold surface is
cooled by endothermic chemical reaction.
3. The cooling garment of claim 1 wherein said cold surface is
cooled by frozen chemical.
4. The cooling garment of claim 1 wherein said hydrophobic spacer
means is synthetic fiber batting.
5. A garment for cooling the body of a wearer fashioned of layered
components into a generally rectangular garment having opposite end
edges and opposite side edges, said garment having a head opening
in a generally central location for accommodating head and neck of
said wearer, front and rear panels, defined by said head opening,
for overlaying chest and back of said wearer respectively, said
garment having an inside surface being the surface closest to the
body of said wearer, said front and rear panels comprising layers,
presented here in an order starting with the claimed layer closest
to said inside surface as follows: a spacer layer of a vapor
permeable hydrophobic material on the inside of a heat absorbing
layer having a temperature below the dew point of water with a
substantially unrestricted vapor travel between the wearer and the
heat absorbing layer.
6. The cooling garment of claim 5 wherein said heat adsorbing layer
is comprised of multiple quilted sections wherein the space between
the said multiple quilted sections forms a substantially vertical
channel.
7. The cooling garment of claim 5 wherein heat adsorbing layer is
cooled by a endothermic chemical reaction.
8. The cooling garment of claim 5 wherein heat adsorbing layer
comprises a sealed container containing a frozen chemical.
9. The cooling garment of claim 5 wherein said vapor permeable
hydrophobic material is synthetic fiber batting.
10. The cooling garment of claim 5 wherein a vapor permeable but
waterproof membrane is placed next to said heat absorbing
layer.
11. The cooling garment of claim 5 wherein an insulating layer is
placed on the outside of said heat adsorbing layer.
12. The cooling garment of claim 1 wherein said cold surface is
comprised of multiple quilted sections wherein the spaces between
the said multiple quilted sections forms substantially vertical
channels.
13. The process of claim 1 with the added step of draining said
liquid water off of said cold surface and away form said body.
Description
FIELD OF THE INVENTION
The present invention relates to body garments capable of cooling
the human body. This invention cools the body by surrounding it
with a dry and cold environment and shielding it from outside heat.
The dry environment within the garment allows evaporative cooling
of the body. The body is also cooled by the cooling of the air
immediately next to the body by the absorption of heat by a phase
shift of a material. The phase shift material is used to dry the
immediate environment around the body.
DESCRIPTION OF THE PRIOR ART
Body garments for the purpose of cooling appear in the patent
record taking many shapes and forms. However, most of these patents
regard body garments that cool through a closed circulation system
of a cool liquid through a piping network incorporated into a
garment or through the specially constructed garment itself having
its own circulatory network. Another focus of the prior art
concerns cooling apparatus that cool through evaporative means.
These devices are open systems, as opposed to the closed
circulation systems mentioned above, that release cool air or vapor
onto and over an individuals body to cool through evaporative
means. Another patent uses the phase shift of a material in a vest
to cool a person but makes no reference to the removal of moisture
as a method of cooling by increasing the evaporation of moisture
from the wearer or a means of keeping a person comfortable. The
present invention works in a different fashion than these above
mentioned patented inventions. It keeps the body comfortable by
absorbing heat directly from the body and by removing moisture away
from the immediate environment around the body and condensing it on
a cold surface. Thus reducing the relative humidity next to the
body and increasing the evaporative cooling of the body and finally
shielding the body from environmental heat. Experiments done by the
inventor show that the transfer of body heat to a heat sink is more
efficient and comfortable if the heat sink is used to reduce the
humidity of immediate environment around the body and encourage the
phase shift cooling that occurs when perspiration evaporates;
rather than trying to absorb heat directly by placing the cold
surface directly next to the body. This is because blood flow
varies relative to the surface of the body and heat is tolerated
better by some parts of the body than other parts. The body
compensates by sweating more in some places than others (arm pits)
and effects pilo erections of surface hair as well as contracts
capillaries near the skin to keep other places warmer. Typically
when a cooling vest that uses a cold surface placed next to the
skin is used several things occur. First evaporation of moisture is
prevented due to a high humidity immediately established above the
skin Second if the cold surface is to be effective it must be
colder than usual for the skin as usually vests cover only a small
portion of the body. This causes constriction of small capillaries
below the surface of the skin and the contraction of muscles
raising small hairs on the skin (goose bumps). Thus one system on
the body fights the method of direct cooling the body by an
application of a cold surface as found in circulated water systems
or systems with cold packs of frozen chemicals. Finally different
parts of the body maintain different temperatures and the body so
regulates. No cold surface system can practically compensate for
this as different activities require different temperatures. The
human body is designed to be surrounded by different temperature
air and can compensate for this if the humidity of this air is low
enough. And in hot environments if the temperature of the air can
be reduced. The application of a cold surface directly to the body
is inefficient and uncomfortable.
The present invention uses a cold surface to condense moisture out
of the immediate environment next to the body. The cold surface is
provided by the frozen quilted outer part of the garment. Channels
are then provided between the quilt packages to remove the
condensed moisture from the vest. The person is cool and dry.
For argumentative purposes the prior art is presented as follows.
U.S. Pat. No. 3,507,321, issued to James R. Palma on Apr. 21, 1970,
discloses clothing for cooling and heating the body. Palra's
clothing affects the human body from the neck down by strategically
locating heating coils and cooling conduits through the clothing.
Temperature sensors are also incorporated into the clothing for
accurate, electrical temperature control of the clothing. Moisture
control is not considered.
U.S. Pat. No. 3,570,264, issued to Daniel L. Curtis on Mar. 16,
1971, discloses an evaporant cooling system comprising a light
weight garment having a plurality of tubes connected in a parallel
arrangement within the garment for the purposes of cooling the
individual wearing same. This invention includes an inlet and an
outlet manifold for circulating a liquid water-ammonia solution
from a storage tank through the tubes. An exhaust port is also seen
in fluid communication with the tubing for allowing the expended
evaporant, the ammonia, to leave the system and further cool the
individual. This is a cold surface system which cannot compensate
for the bodies needs.
U.S. Pat. No. 3,610,323, issued to Dan E. Troyer on Oct. 5, 1971,
also discloses an evaporative cooling garment to be worn by an
individual This garment is seen as a vest-like coat having a
plurality of passageways incorporated therein to create a coat from
these side-by-side passageways. These passageways are also seen as
having a plurality of openings thereon. When used, the Troyer coat
is supplied from a reservoir with a quantity of liquid coolant
comprising a water and refrigerant, preferably Freon, through an
inlet valve. As the body is cooled the refrigerant evaporates,
leaves the system, and is replaced from the reservoir until the
[such] refrigerant has been depleted. No consideration is made for
the condensing of moisture from the body is made.
U.S. Pat. No. 3,744,053, issued to Eugene K. Parker on Jul. 10,
1973, discloses liquid loop garments for heating and cooling the
body of and individual. This system is a closed system, releasing
no liquid or gas for either heating or cooling purposes. Parker's
garments are constructed of two, liquid impervious, materials
layers having insulation as well as other materials attached
thereto. This again is a cold surface system which cannot
compensate for the needs of the body.
Jumping ahead to U.S. Pat. No. 4,949,375, issued to Robert L.
Nathans on Dec. 25, 1990, we see a mat utilizing the same type of
closed system for circulating a fluid for cooling purposes that was
disclosed in the Parker patent.
U.S. Pat. No. 4,998,415, issued to John D. Larsen on Mar. 12, 1991,
discloses a body cooling apparatus including a tubing system for
circulating a fluid that is moved not only through the tubing
within the apparatus but through a compressor and a condenser in
order to remove heat away from the body of an individual wearing
the apparatus. Larsen's apparatus also includes a head cooling
apparatus integrally connecting to the tubing of the main, body
supported, apparatus for cooling the head of an individual. This
once again is a cold surface cooling system that cannot compensate
for the needs of the body.
U.S. Pat. No. 5,289,695, issued to Parrish and Scaringe on Mar. 1,
1994 discloses a device for adsorbing water with a desiccant.
Desiccants such as calcium chloride are mentioned. The exothermic
heat generated by the hydration of this desiccant is blocked from
the body by an open cell foam layer. Thinsulate by 3M could be used
to help insulate along with the open cell foam. A molecular sieve
is mentioned as well as an adsorbent or absorbent material. The
desiccant can be sealed in a plastic bag which can be opened to
initiate adsorption. Valves and pumping of fluids from the
desiccant are mentioned. The use of a cold surface to reduce the
humidity of the immediate environment is not mentioned.
U.S. Pat. No. 4,964,282, issued to Christopher S. Wagner on Oct.
23, 1990, discloses a detachable bulletproof vest air conditioning
apparatus. Wagner's apparatus comprises a piping system that
connects to a pre-cooled air source and ducts and channels the air
into the interior of the vest, between the vest and the individual,
to cool the wearer of said vest.
U.S. Pat. No. 5,146,625, issued to Sandra L. Steele and Harry W.
Nettleton on Sep. 15, 1992, discloses a vest with clothe pockets
that contain a phase shift material. No provision is made for the
removal of moisture. No
provision is made for providing channels to drain the condensed
moisture from the vest. No provision is provided for forced
air.
U.S. Pat. No. 5,289,695, issued to Clyde F. Parrish and Rpbert P.
Scaringe on Mar. 1, 1994, discloses a vest with a desiccant pad to
absorb moisture and a foam to transport moisture to the pad. No
provision is made to condense the moisture or channel it out of the
garment. Rather the moisture is chemically absorbed. This patent
fails to teach that with a cold surface; a chemical desiccant is
not necessary to remove moisture, if the moisture can be channeled
in some way from the vest.
U.S. Pat. No. 5,072,455, issued to Thomas A. St. Ours on Dec. 17,
1991, discloses multiple pocketed vest with coolant packs. No
provision is made for the removal of moisture. No provision is made
for wicking the moisture to the cold packs nor is any provision
made to channel the moisture out of the vest. The use of forced air
is not considered.
U.S. Pat. No. 4,170,793, issued to Scott T. O'Brien on Oct. 16
1979, discloses a vest with a cotton inner lining which wicks
moisture from the individual and allows for evaporation of
moisture. No provision is made for actively absorbing the heat of
the individual through a heat sink nor is there any provision for
condensing the moisture of the individual so that it can be
transported from the vest. No provision is made for the removal of
moisture with forced air.
U.S. Pat. No. 5,415,222, issued to David P. Colvin and Yvonne G.
Bryant on Mar. 1, 1994, discloses a vest which has pouches of a
coolant which does not cover the entire surface of the vest but
rather allows evaporative cooling to occur where the pouches do not
touch the wearer. No provision is made for the condensation and
removal of moisture from the vest. Moisture is not condensed and
channeled out in liquid form but rather is allowed to passively
evaporate through pours in the vest. There are no channels for the
transport of moisture or provision for the wicking of moisture to
the channels.
Exothermal Tech makes a vest which has a phase change material
designed to phase shift around 70F in a sectioned plastic bag which
is encased in a cloth shell. The sections are large and run
diagonally no provision is made to wick moisture to these plastic
bags. The close and immediate contact of the heat sink to the skin
of the wearer prevents the removal of moisture from the body. The
relatively high temperature of the phase shift material is
insufficient to condense the moisture. There are no vertical
channels in the sides of the vest to transport the condensed
moisture. There is no provision for the removal of moisture with
forced air.
SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the invention to provide a
convenient and inexpensive body cooling garment that does not
require the use of expensive refrigerants yet still is capable of
cooling the body. The present invention is a vest or garment to be
worn either under protective clothing or alone and to protect a
person from environmental heat. The vest is designed to absorb
humidity from the body and condense it on a cold surface. It uses a
phase shift material such as melting ice as a heat sink. This heat
sink also limits environmental heat from the outside environment
from effecting the body. The garment absorbs and transport the
moisture given off from the body through initial capillary action
in conjunction with vapor transfer which is effected by the
reduction of humidity immediately next to the body or with the
additional use of forced air. The vest after a few minutes reduces
the relative humidity immediately next to the wearer to the point
where perspiration is rapidly evaporated into the dry immediate
atmosphere next to the body and condensed on the cold surface in
the vest.
One embodiment of the invention is lined with connected plastic
packages of a phase shift material (frozen water) with a material
which would provide an air space from the cold surface and allow
moisture to condense on the package. The term wicking material is
often used when referring to the transfer of water vapor through a
material especially when referring to garments. Patagonia brand
polyester pile jackets are said to wick moisture to the outside of
the jacket. Travelsmith brand bras made of polyester materials are
said to be moisture wicking when it could be understood that they
are vapor permeable. The material used to provide the air space
between the skin and the cold surface would be of this type. It
would not be adsorbent. The moisture condensed on these cold packs
is then conveyed down formed channels between the cold packs and
then dripped from the vest. The width and spacing of the vertical
channels is determined by the rate of condensation and the surface
tension of the perspiration and the size of droplets formed. The
material, between the cold packs and the wearer, is a synthetic low
absorption material such as polyester batting or Nomex.TM. batting
held in place by a fabric screen, but would not be limited to such.
The batting keeps the frozen water packages suspended off the
surface of the body to allow condensation to form droplets on the
cold surface and flow to the channels. Any material other than
batting that would keep the cold surface in the immediate close
proximity to the body would do. The body is cooled by passive
absorption of heat by the cold dry air surrounding the body and by
the phase shift of perspiration to a vapor encouraged by the
dryness of the immediate environment around the body.
The inventor conducted an experiment where a double layer of cotton
material was soaked in water to represent the skin of a hot
individual this was laid on a flat marble slab to maintain a
constant temperature. On top of this was placed 3/16 in. layer of
polyester batting. Then two electrical sensors, each constructed of
a pair of 1/16 in stainless steel rods held 1/16 in apart were laid
on the polyester batting. One electrical sensor was wrapped in wet
cotton and the other in dry cotton. Current flow could be measured
in the electrical sensor (electric hygrometer) wrapped in the wet
cotton but none in the dry. (The wet cotton was soaked and then
wrung out.) Next another layer of 3/16 in polyester batting was
placed over the electrical sensors. This polyester spacer permits
the transfer of water vapor yet does not readily transfer liquid.
Finally a large flat bag of frozen water sealed in mylar was laid
on top of all. This containment structure of frozen water (ice) was
quilted by sealing 1/4 in. wide seams every 11/2 inch to form 11/2
inch squares with channels between them; like a quilt. So we have
the skin represented by the soaked cotton and then a double layer
of polyester with electrical sensors in between and a cold
channeled surface (heat absorbing means). Intuitively we would
expect a current flow between the rods of the electrical sensor
wrapped in wet cotton to remain the same and the sensor wrapped in
dry cotton to become wet and show a flow of electricity. What in
fact happens is the dry cotton electrical sensor initially gains a
small flow of current but then drops rapidly so that no current
flow is detected. The wet cotton electrical sensor rather than
having the current flow remain constant shows almost an immediate
drop in conductivity. This drop in current flow across the wet
cotton continues to drop to the point where no current can be
detected after about an hour. Counter to what is expected the wet
cotton on the two stainless rods is rapidly drying out. This drying
is happening even though the soaking wet cotton on the marble slab
is still very wet. The quilted bag of frozen water is now wet. If
this set up is tilted the water condensed on the quilted cold
surface begins to run down the channels and out of the apparatus.
By completely covering the soaking wet cotton with the quilted cold
surface suspended above it by the polyester batting air flow from
the outside is reduced or practically eliminated and a dry arid and
cool environment is created next to the soaking wet cotton surface
representing the skin. This surface begins to cool by two processes
i.e. evaporative cooling and the absorption of heat by the cold air
next to it. As a control experiment, if the soaked cotton surface
representing the skin is left dry instead of soaking it with water
no condensation can be found on the cold surface next to the
polyester. It remains dry although the other side where it is
exposed to air in the room condensed moisture. This control
experiment confirms the condensed moisture in the first experiment,
is moisture that evaporated from the wet cotton simulating the
skin. As to why the electrical sensor wrapped in dry cotton begins
to conduct electricity and then stops is believed to be due to
initial wicking from the soaking wet cotton surface until
evaporation exceeds the wicking in the polyester. The inventor does
not wish to be held to this explanation.
Polyester used in this apparatus and in the invention does not
really wick as cotton does, however it does permit water vapor to
transfer and limits condensed moisture transfer. The inventor
refers to this material as a vapor wicking medium as opposed to a
capillary action wicking medium. Other materials beside polyester
would be suitable, in fact most man made fibers will work, while
untreated cotton does not work. Untreated cotton just becomes
saturated with water and directly conduct heat to the cold surface.
A garment incorrectly using a material with the water absorbing
characteristics of untreated cotton, will make the wearer feel
clammy and wet.
The cooling vest works in a like manner to the experiment described
above. Its effectiveness in cooling an individual is more than the
amount of calories transferred by simple conduction to the frozen
water in the vest. The utilization of the cooling effect of the
phase change of perspiration into a vapor by the reduction of
absolute humidity next to the skin and the drop of water vapor
pressure allowing more perspiration to be evaporated significantly
enhances the effective cooling and comfort of the vest. This is so
because the water (perspiration) is continually channeled from the
vest. This efficiency is further enhanced by the physiological
demands of the body. The body self regulates the evaporation of
perspiration in different parts of the body according to need. It
does so by among others varying the amount of sweat and controlling
the air flow immediately next to the skin by the selective erection
of hair on the skin and the contraction of capillaries under the
skin.
The construction of the cold surface to condense the moisture on is
important. It must be channeled to allow the condensed moisture to
leave the vest. If the vest is to be used horizontally a vapor
permeable but water proof membrane must seal FIG. 3, 13 the
channels from the polyester. Examples of this is Gortex.TM. or the
house wrap Tyvek .TM.. These allow water vapor to pass but prevent
the back flow of water. This set up is used when gravity alone will
not be enough to channel condensed water from the vest. The
quilting in any shape square, round, irregular, of the cold pack is
an excellent method of providing channels in the vest for moisture
removal. By making the cold surface of 11/2 inch squares with a 1/4
channel allows flexibility in the vest. Also by having the squares
connected it seals the immediate environment next to the skin from
out side air allowing the air to be dried and cooled. If cold packs
are merely attached end to end on only one or two sides as in the
Steele vest U.S. Pat. 5,146,625, a pocket must be sewn into a
cooling vest or garment to hold each row of cold packs, however if
the cold packs are quilted then the vest becomes easier to make.
Also water does not collect from condensation and wet the wearer at
the seam of the vest pocket. Further the necessity to make sewn
pockets necessitates that the size of the cool pack be larger than
otherwise or the seams from the pockets will take up a large
portion of the vest. This creates another problem in that the large
cold pack which is most often filled with a liquid or powder
settles to the bottom and unnecessarily thickens and more
importantly adds weight to the vest. An experiment with a 4 in by 4
in polyethylene baggy of water will demonstrate that to cover a 4
in sq. surface requires a bag filled almost two inches thick.
However, if a 4 in by 4 in quilted bag, if quilted with three bags
across and three down, the same surface can be accommodated with a
thickness of much less than one inch and consequently less than
half the weight. Each bag in tension supports the other bag.
A lip forming a gutter FIG. 3, 14 is incorporated in another
embodiment on some of the horizontal channels of the cold surface.
A drain hole FIG. 3, 15 is provided to convey moisture out the
drain hole to the outside of the vest. The addition of an up turned
edge of plastic sealed to a horizontal channel would form a gutter
at the bottom of a row. It is used to channel condensed moisture
through a small hole in the channel to the out side of the cold
pack.
In situations where a large individual or individuals who perspire
a lot are very active it is possible that the evaporation of
moisture in the immediate dry cold environment next to the skin
could be overwhelmed. It would be essential to prevent the
saturation of the vest and direct thermal contact between the skin
and the cold pack surface. In these cases the vest would be
equipped with a perforated tubing network to pump in forced air
from a belt mounted blower or otherwise. Vests require a minimum of
30 psi to operate effectively. Channels already formed in the vest
could used to deliver the air where a downward flow would increase
the flow of condensed moisture down the quilted cold surface and
out of the vest. The forced air would be either user controlled or
automatic using an electrical sensor to determine the absolute
humidity in the immediate environment next to the skin and compare
this to the temperature and absolute humidity outside the vest or
garment. The object being to prevent saturation of the vest and a
chilling of the wearer. Thermal contact with the wearer would
shorten the length or time the cold surface would be effective.
Experiments done by the inventor has shown that the effective
cooling time of the vest is strongly effected by outside
environmental heat melting (phase shift) the cold surface. In a
very hot environment it would seem that putting a heavy coat over a
cooling vest or garment of the type above would be counter
productive. However this not the case. Providing insulation to the
outside of the garment significantly increases the length of time
the cold surface can effectively condense moisture and cool the
body. The best insulation by weight is an aerogel silica foam as
manufactured by Aspen Systems Incorporated, Marlboro, Mass. Also by
providing a reflective layer such as mylar is also effective. When
price is considered, the most effective outside insulation is
polyfoam a polyester closed cell foam used in packageing.
BRIEF DESCRIPTION OF THE DRAWINGS
Drawings
FIG. 1
1. Blower
2. Battery
3. Garment
4. Connection of blower to tubing network under vest
FIG. 2 Cross Section of Vest
5. Phase shift material package (ice mat) (cold surface)
6. Moisture channel
7. Air tube
8. Vapor wicking medium (pellon)
9. Infrared reflective surface
10. Insulation to protect from environmental heat (polyfoam)
11. Inner garment shell (textiline)
12. Outer garment shell (textiline)
FIG. 3 Cross Section of Vest showing Preferred Embodiment(s)
5. Phase shift material package (ice mat) (cold surface)
6. Moisture channel
9. Infrared reflective surface
10. Insulation to protect from environmental heat
12. Outer garment shell
13. Vapor permeable but water proof membrane (Gortex.TM.)
14. Lip to form gutter
15. Hole
Similar reference characters denote corresponding features
consistently throughout the attached drawings. Round brackets are
to help identify and to clarify but are not intended to limit the
materials used.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(s)
The present invention relates to independent and portable body
garments that cool the body. The present invention is distinct from
those already patented in that provides for the removal of moisture
from the body both
to keep the person comfortable and to cool the body. The invention
allows the wearer to remain both cool and dry in very hot
conditions. The vest is also designed to use a cold pack 5 with a
surface designed to reflect infrared spectrum light 9. A mylar
material such as used in "space blankets" is presently used with
the reflective side out and a non-reflective side next to the body
thus heat from the body is not reflected back to it but is
absorbed. The cold pack (packaged phase shift material) 5 is
further designed to be sectioned into rectangular sections which
are attached on multiple sides to be quilt like in construction.
Presently a sheet of approximately 11/2 inch squares is used with
approximately 1/4 in seam between packages top, bottom, and sides.
Five packages thus measuring a little less than 10 inches across;
the spacing of the vertical channels should allow transport of
condensation (perspiration) horizontally with out dripping. This
also eliminates the necessity of multiple fabric pockets in the
vest. Vests with cold packs attached only end to end require a
fabric pocket to hold the packs . The tracks between the quilted
cold packets form a channel 6 for the removal of condensed
humidity. Moisture condenses on the pack and moves across it and
down between the packs uninterrupted by any cloth pockets and
ultimately out the bottom of the vest. The moisture is transported
from the body to the cold packs by a material 8 that allows vapor
transport of water. Both polyester batting and Nomex.TM. batting if
treated work well. This spacer for the removal of moisture is very
important. In other vests the condensed moisture that condenses on
the packet collects at the bottom of the fabric pocket or transfers
back through the vest and wets the wearer. This wetness inhibits
evaporative cooling of the wearer due the reduction of the surface
area of the skin. Surface irregularities and hair follicles are
covered with rounded beads of moisture.
The quilted cold pack 5 in this vest is made flexible by the
addition of multiple channels on the pack on more than one axis. It
also limits the phase change material from collecting at the bottom
and ballooning the packet after it returns to a liquid state. The
sectioning allows a thinner vest to be made as smaller cooling
packs are possible due to the limitation of the seam width of
individual pockets in other vests. If individual pockets were sewn
into the vest, there would be many fabric seams where there would
be no phase change material to absorb the heat. The bottom of each
small phase change material pack supports the other without a sewn
pocket. The quilted cooling pack also allows a staggering of seams
of phase change material when two layers are used, hence providing
continuous coverage of the body. This construction also allows a
much lighter garment to be made as the elimination of usually
fabric pockets allows smaller packets to be used of the phase
change material. Larger packets are used in present vests due to
the fact that the phase change material such as water sags as a
liquid and must be of a certain size to allow adequate coverage of
a body and allow for a minimum number of sewn pockets in a vest. By
using a quilted pattern of at least three rows by three columns
each package of phase change material supports the other and a vest
can be made thinner. The vest uses five by ten package cold packs
to allow the formation of channels to convey downward moisture. On
legs or arms an even smaller package quilt would be used to further
reduce the thickness and weight.
The construction procedure presently used for a vest is as follows
where textiline.TM. is a mesh like fabric as used on trampolines,
polyfoam.TM. is a packing material made of close celled
polyethylene, ice mat is the quilted cold surface and pellon.TM. is
a polyester batting material.
1. Cut out pattern of textiline fabric for both inside FIG. 2, 11
and outside 12 of vest shell. Cut 2 in. velcro pieces to length if
velcro is to be used for fastening other wise disregard velcro. Two
strips will be sewn across the front of the vest, loop out.
2. Completely sew bottom front velcro on the outer textiline 11
only.
3. Sew top front velcro only on seam farthest the head hole. We
will sew the bottom seam of the top velcro later to hold the
insulation and 1 inch velcro sticky type in place.
4. Sew back pieces of 2 in velcro on and roll the loose ends to
prevent the from catching on everything.
5. Lay large textiline vest shell pieces 11 and 12 together and sew
hole for head.
6. Cut out from insulation pattern two pieces of pellon insulation
8.
7. Install pellon 8 between two pieces of textiline 1 land 12 by
pulling outside layer of vest through the head hole cut out in the
pellon 8.
8. Cut out from 1/8 poly foam 10 two pieces using the insulation
pattern.
9. Install poly foam 10 on top of pellon 8 under outer layer of
textiline 12. You will have a sandwich of textiline with two layers
of pellon and two layers of poly foam later separated with a layer
of ice mat (cold surface) shiny side facing the polyfoam.
10. Along the bottom seam line of the top velcro strip in the
front, place two 1 inch velcro sticky tape strips inside hook down
between the pellon 8 and the polyfoam 10. Place them at least four
inches from the edge. Should no 2 in velcro be used made this seam
half way up front and back of vest. Sticky tape velcro should go
perpendicular to the seam and half above the seam and half below.
They will be used to stick the ice mat 5 in place in the vest. We
will peel back the sticky tape and stick the ice mat 5 (cold
surface) firmly to the sticky side of the velcro. Other wise the
ice mat 5 can be held alone between textiline 11 and 12 the stick
tape velcro can also be omitted.
11. On the back of the vest there is a seam line as well do the
same again with the 1 in velcro. The hook side of the sticky tape
velcro if used should face the pellon 8.
12. Cut the ice mat5(cold surface) pieces for the front and back of
the vest to allow for neck hole.
13. Install ice mat 5 between the poly foam 11 and the pellon 8.
The pellon 8 being the inside of the vest the poly foam 11
insulating the outside. Peel back the outside of the one inch
velcro exposing the sticky back and firmly anchor the blue side of
the ice mat. Won't stick if mat is cold or wet. The silver mylar
side should shine outward to reflect heat trying to get through the
vest . If dividing seams are sewn in the front and back of the
fabric 11 and 12; then four ice mats two front and two back must be
installed.
14. Bind outside of vest using care not to puncture the ice mat(s)
5.
15. The vest is completed other garments for legs etc. are made
simular.
Another embodiment uses to enhance the removal of moisture from the
garment the use of forced air is used. Experimentation has shown
that a minimum of 30 psi is needed to effectively remove moisture
from a vest of this type. The forced air is delivered through
perforated tubes 7 in the vest in a network to distribute the air;
although the channels between the phase change material could be
used as a vector for the air flow. The air is supplied
independently from a compressor or a belt mounted blower 1. The
direction of the air flow would be downward to encourage the flow
of moisture from the cold pack.
FIG. 3 shows two other distinct embodiments. First is a Gortex.TM.
film described as vapor permeable but water proof membrane 13
preventing back flow of condensed water from the cold surface 5.
This is also sealed, in another embodiment, to lips 14 to
positively remove moisture through hole or moisture transfer means
15 to the outside of the garment. (cotton could be used to wick
moisture through the hole but in this particular embodiment would
not be necessary) Also shown in FIG. 3 is the gutter arrangement on
the horizontal rows of the cold surface 5. The lip 14 traps water
as it condenses and runs down 5 and instead of allowing it to drip
from the bottom of the vest; it moves the condensed water to the
outside of the vest where it would be used again in evaporative
cooling. In this case the outside insulation 10 would be a vapor
wicking medium such as pellon but not limited to such. Experiments
show that the additional phase shift of moisture on the insulating
surfaces of the outside of the garment significantly lengthens the
cooling time of the garment.
Although the invention has been described and illustrated in
detail, it is to be understood the same is by way of illustration
and example and is not to be taken by way of limitation. The spirit
and scope of the present invention are to be limited only by the
terms of the appended claims.
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